1. Field of the Invention
The present invention relates to a liquid crystal display (LCD), and more particularly, to a color filter substrate for an LCD and a fabricating method thereof.
2. Discussion of the Related Art
Until recently, display devices generally employed cathode-ray tubes (CRTs). Presently, many efforts are being made to study and develop various types of flat panel displays, such as liquid crystal displays (LCDs), plasma display panels (PDPs), field emission displays (FEDs), and electro-luminescence displays (ELDs), as substitutions for CRTs.
Of these flat panel displays, the LCD has high resolution images, lightness, thin profile, compact size, and low voltage power supply requirements.
FIG. 1 is a schematic view of an LCD according to the related art.
In FIG. 1, an LCD 11 includes a color filter substrate 5, an array substrate 22, and a liquid crystal layer 14 interposed between the two substrates 5 and 22.
The array substrate 22 as a lower substrate includes a data line 15 and a gate line 13 to define a sub-pixel region P, a pixel electrode 17 and a thin film transistor T as a switching element in the sub-pixel region P.
The color filter substrate 5 as an upper substrate includes red, green and blue color filter patterns 8 (R, G and B) corresponding to the respective sub-pixel regions P to display red, green and blue colors, respectively, a black matrix 6 between the adjacent color filter patterns 8, and a common electrode 18 on the color filter pattern 8 and the black matrix 6.
In the LCD of FIG. 1, red, green and blue sub-pixels, which have red, green and blue color filter patterns R, G and B, respectively, constitute one pixel to display color images.
FIG. 2 is a cross-sectional view of an RGB color filter substrate for an LCD according to the related art.
In FIG. 2, an RGB color filter substrate includes red, green and blue color filter patterns 130a, 130b and 130c, and further includes a black matrix 120 having first, second and third opening 125a, 125b and 125c corresponding to the red, green and blue color filter patterns 130a, 130b and 130c. A planarization layer 140 is disposed on the color filter pattern 130 to planarize the RGB color filter substrate.
Recently, to increase brightness of displayed images, the color filter substrate includes a white color filter pattern as well as red, green and blue color filter patterns.
FIG. 3 is a cross-sectional view of an RGBW color filter substrate for an LCD according to the related art.
In FIG. 3, the RGBW color filter substrate includes red, green and blue color filter patterns 230a, 230b and 230c like the RGB color filter substrate of FIG. 2, and further includes a white color filter pattern 230d. 
FIGS. 4A to 4G are cross-sectional views of a fabricating method of an RGBW color filter substrate for an LCD according to the related art.
In FIG. 4A, a light-shielding material is deposited on a substrate 210 and patterned to form a black matrix 220. The black matrix 220 includes first, second, third and fourth openings 225a, 225b, 225c and 225d corresponding to respective sub-pixel regions.
In FIG. 4B, a red color resin 229 is deposited on the substrate 210 having the black matrix 220.
In FIG. 4C, the red color resin 229 (in FIG. 4B) is patterned to form a red color filter pattern 230a in the first opening 225a. 
In FIG. 4D, a green color resin is deposited on the substrate 210 having the red color filter pattern 230a and patterned to form a green color filter pattern 230b in the second opening 225b. In other words, the green color filter pattern 230b is formed in a similar method of forming the red color filter pattern 230a. 
In FIGS. 4E and 4F, blue and white color filter patterns 230c and 230d are formed in the third and fourth openings 225c and 225d in a similar method of forming the red and green color filter patterns 230a and 230b. 
In FIG. 4G, a planarization layer 240 is formed on the color filter pattern 230.
In the fabricating method of the related art RGBW color filter substrate, since the RGBW color filter substrate includes the white color filter pattern, in addition to patterning processes to form red, green and blue color filter patterns, a patterning process is needed to form the white color filter pattern. Therefore, processes and costs to fabricate the color filter substrate increase.